Residential Air Conditioning & Heating Servicehvac cu minisplit

Common A/C Unit Questions

1. What size HVAC system should I have?

Contrary to popular belief there, is no rule of thumb for sizing a system to a home. Depending upon the construction of your home, one (1) ton of air conditioning can cool anywhere from 300 to 800 square feet of home. The only way to insure the size of the system you purchase will be large enough to cool your home, but not any larger than you need, is to have your home’s individual cooling and heating needs evaluated by a licensed professional.

2. How are the sizing capacities of heating and cooling systems measured?

The heating and cooling systems are sized according to their tonnage. One (1) ton equals 12,000 BTU/H. Residential systems can range from 1- 5 tons.

3. How is the efficiency of an air conditioning system measured?

The SEER (seasonal energy efficiency ratio) is the amount of cooling your system will deliver per dollar spent on electricity. The EER (Energy Efficiency Ratio) of a particular cooling device is the ratio of output cooling (in Btu/hr) to input electrical power (in Watts) at a given operating point. The higher the SEER and EER, the more efficient the system will be. The SEER has the same units of Btu/W·hr, but instead of being evaluated at a single operating condition of 95F ambient, it represents the expected overall performance for a typical year’s weather in a given location.

4. How can I increase the efficiency and life of my home’s cooling and heating systems?

One of the best things you can do to extend the life of your HVAC equipment is to clean and replace your filters as needed. In addition, yearly maintenance in the spring and fall is highly recommended to ensure the system is operating at peak efficiency.

5. Is a larger system better?

No. A larger system with more capacity delivers less comfort and costs more to operate. An air conditioner is at its lowest efficiency at start up. A system with too much capacity will cool the house too fast (short cycling), turning on and off repeatedly over an extended period. Also keep in mind that an air conditioner only removes humidity when it’s running, so a system with shorter run cycles doesn’t remove humidity from the air very well.

7. Should I try to keep my system from running too much?

Every time your system starts up, it uses a lot of electricity and may not produce much cooling. Usually a system that is too small to cool the home is more economical to run but delivers less comfort. Even though it runs nonstop, it will usually consume less power than a larger system that cycles on and off. As a rule of thumb, a unit that is either on or off is less expensive than one cycling on and off.

8. What temperature should I set my thermostat?

Obviously, the time of year becomes a big factor for desired temperature settings. In summer months, the average temperature setting is 76°-78°, and 69°-71° during the winter. Remember, when leaving your house; try to avoid drastic temperature changes. Do not set your temperature back more than 5°; this will cause your unit to work harder to achieve the desired temperature setting.

9. What are programmable thermostats and what are their advantages?

There are numerous programmable thermostats available on the market today that offer many new and exciting features. And because they are electronic, they are more accurate and efficient than thermostats that contain mercury. With programmable thermostats you can control the temperature in your home at different times of day without ever touching your thermostat. Because everything is automatic, you will never forget to change the setting on your own.

10. How often should I have maintenance done on my air conditioner and what can I do on my own?

Great question! How long do you want your HVAC system to last? In order to ensure maximum efficiency and life span, you should have planned maintenance performed on your air conditioning system twice a year. This allows us to foresee any potential problems and prevent costly breakdowns. Our Planned Maintenance Agreements (PMA) can be custom designed for your home or office.

11. How much does a new replacement system cost?

Due to the numerous brands and models, equipment should be determined by the individual’s specific needs. For example, air quality, humidity control, and overall efficiency can be dramatically improved by installing better equipment. So, depending on the situation, this question can best be answered by doing a thorough evaluation of your home and your existing situation. We offer some excellent financing options to make your investment convenient. There is never a charge for an in-house energy assessment from one of our comfort advisors. This takes approximately 60 minutes and you can schedule an appointment by calling us at 210-988-9322 or going online at

12. Are there any air conditioning systems that are safe for the environment?

Yes. All manufactures have developed new systems that contain the environmentally friendly R410A, or Puron, refrigerant.

13. Why are humidifiers used more in heating than cooling?

When cool outdoor air enters a home it tends to dry out as it warms up, which increases the static electricity in the home and causes sinus problems. Adding a humidifier will help add moisture back into the air and limit sinus problems. In the summer, humidity levels are already high and the goal becomes to dehumidify the air, or take out moisture in the air. This water vapor is called condensation. The average comfort range for relative humidity in a home is from 40-50%.

14. During the heating season, my heat pump delivers warm air, but not hot air, and will operate for long periods of time. Is that normal?

This was a common problem with heat pumps for many years, but manufacturers have come a long way in heat pump design and engineering. New heat pumps can produce supply temperatures of 110F+. Yes, this is normal.

15. How do I know if my A/C unit is big enough?

Before purchasing any replacement equipment for your home, you should make sure your system is sized properly. Your ductwork has a big impact on how well your system operates as well. Poor quality and/or design can lessen your airflow and cost your money. Our comfort consultants can provide you a heat load calculation to determine the proper size and make the appropriate recommendation. Remember, bigger is not always better.